1. Field of the Invention
The present invention relates, in general, to an apparatus for producing composite gas for fabricating metal matrix composite materials (MMCMs) in a liquid metal process and, more particularly, to an apparatus by which composite gas, which is used to fabricate nanoparticle reinforced metal matrix, composite materials, is produced by feeding nano-powders into a pressurized inert gas tank, in which upper rotor and lower fans are mounted, blowing and dispersing the nano-powders around the inside of the pressure tank with rotation of upper and lower blades, and supplying the dispersed nano-powders with inert gas to molten metal by a lance pipe or agitation rotor, which will be fed to a liquid metal mixing process in fabricating composite materials, thereby fundamentally solving the problem that nano-powders are not uniformly dispersed, but agglomerated into clusters during the feeding process, and enabling development of a new process using the composite gas containing well-dispersed nano-powders in inert gas.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Recently, automobile and aviation industries are putting a great deal of effort into developing composite materials using nano-sized ceramic powders, carbon nanotubes (CNTs) and carbon nanofibers (CNFs) in order to develop materials that have excellent mechanical properties and lighter weight compared to those of existing materials.
However, there is no solution to effectively solve the problem of agglomeration or clustering of nano-powders in the fabrication of metal matrix composite materials in a liquid metal process, thereby creating a problematic situation for improving dispersion and wetting of nano-powders in liquid metal and developing an efficient process because of a limited feeding method of nano-powders to molten metal.
Although until now, agglomerated or clustered nano-powders are dispersed using high shear stress obtained by mechanical agitation or by using ultrasonic waves in a liquid metal process, satisfactory results have not yet been obtained.
Further, in regard to development of new fabrication processes, a special effect has not yet been obtained because of the limited feeding method of nano-powders. For example, although, in the case of metal matrix nanocomposites (MMNC), a stir casting process is generally used for fabricating metal matrix composite materials in a liquid metal process, such a method is not yet complete because it is difficult to disperse nano-powders without agglomeration and clusters in the molten metal.
Therefore, there is a need to develop a new process of feeding nano-powders used to manufacture composite materials, with excellent dispersion and wettability in molten metal, without using excessive mechanical agitation and expensive ultrasonic equipment, and thus to develop a variety of manufacturing processes for composite materials using such a method.